Stabilization Of Clay Soil Using Coir Fibre And Calcium Bentonite

A Final year project on “Stabilization Of Clay Soil Using Coir Fibre And Calcium Bentonite” was submitted by Ajay Kumar (from Sri Sairam engineering college Chennai) to extrudesign.com.

ABSTRACT

Soil is a natural resource. Some waste materials such as calcium bentonite, coir fiber may use to make the soil to be stable. The addition of such materials will increase the strengthening of the soil. Some expecting properties to be improved are CBR value, shear strength, liquidity index, plasticity index, unconfined compressive strength, bearing capacity, etc. the objective of this study was to evaluate the effect of calcium bentonite derived from the combustion of bituminous coal at electric power plants in the stabilization of soft fine-grained clay soil.  The California bearing ratio (CBR) and other strength property tests were conducted on the soil. In soil mixtures of calcium, bentonite is prepared at an optimum water content of 12% and the addition of bentonite resulted in appreciable increases in the CBR of the soil. For water contents 12.5%wet of optimum, CBR of the soil is found in varying percentages such that 5, 10, 15, and 20. We will found the optimum CBR value of the soil is 15%. Increases in CBR value are used to reduce the thickness of the pavement And increase the bearing capacity of the soil.

INTRODUCTION

In India, soils are classified into six groups namely alluvial soil, marine soil, lateritic deposits, expansive soils, sand dunes, and boulder deposits. Encountering land having soft soil for construction leads to attention towards adopting ground improvement techniques such as soil stabilization. Soil stabilization is the process that involves enhancing the physical properties of the soil in order to improve its strength, durability, etc. mixing it with additives. The different types of methods are used for soil stabilization. Soil stabilization using cement, lime, bitumen, Chemicals, and new emerging technology of stabilization by using Geotextiles and Geosynthetic fibers. This project deals with the stabilization of clay soil using calcium bentonite & coir fiber. Since the soil should be stabilized for reducing the cost of the foundation, excavating for more depth. These tests will give the results of the stabilized soil. this stabilized soil is also used to improve and strengthen the foundation and which may bear high strength than the normal soil.

1.1 OBJECTIVE OF THIS STUDY

To strengthen a weak soil and restrict the volume change potential of highly plastic or compressible soil. To study the various geotechnical properties of soil such as maximum dry density, optimum moisture content, California bearing ratio, and unconfined compressive strength parameters by mixing soil with different percentages of coir fiber.

1.2  METHODOLOGY :

In this Study, The stabilization of soil using coir fiber is referred from the literature review then material collection, properties of the material, material expenditure procedure, various % of adding coir fiber, test procedure, and result. 

2. MATERIAL USED

2.1 CLAY SOIL:

Clay is a fine-grained natural rock or soil material that combines one or more clay minerals with traces of metal oxides and organic matter. Clays are plastic due to their water content and become hard, brittle, and non–plastic upon drying or firing.[1] Geologic clay deposits are mostly composed of phyllosilicate minerals containing variable amounts of water trapped in the mineral structure. Depending on the content of the soil, clay can appear in various colors, from white to dull grey or brown to a deep orange-red.

2.3 COIR FIBRE:

• Coir fibre is a natural fibre extracted from the outer husk of coconut and used in products such as floor mats, doormats, brushes and mattresses.
• Other uses of brown coir (made from ripe coconut) are in upholstery padding, sacking and horticulture.

2.4 CALCIUM BENTONITE :

• Calcium bentonite is an absorbent kind of clay that typically forms after volcanic ash ages.
• It’s named after Fort Benton, Wyoming, where the largest source of the clay can be found, but calcium bentonite is found all over the world.

3. TEST METHOD:

• Grain size distribution by sieve analysis
• Liquid limit
• Plastic limit
• Procter compaction test
• California bearing ratio test

SIEVE ANALYSIS:

S.no	Is sieve	Size of Opening (mm)	Mass of soil Retained	Cumulative Mass of soil Retained (g)	Cumulative % retained	% finer
1	4.75	4.75	1.0	0.10	0.10	99.9
2	2.36	2.36	4.0	0.40	0.50	99.5
3	1.18	1.18	30	3.00	3.50	96.5
4	600m	0.600	68	6.80	10.30	89.70
5	425m	0.425	58	5.80	16.10	83.90
6	150m	0.150	240	24.00	40.1	59.90
7	75m	0.75	92	9.20	49.3	50.70
8	pan	<.75	507	50.70	100	0

RESULT

         The result of grain size distribution by sieve analysis test of field soil is represented in Table. From the above analysis, it is clear that the field soil is to be the percentage of finer more than 50% in 75m Sieve. So the soil is recommended as fine-grained soil.

LIQUID LIMIT:

S.no	Weight of Soil (g)	Percentage of Water Content(%)	Number of blows
1	120	24	79
2	120	26	54
3	120	28	35
4	120	30	22

RESULT:

        The result of the liquid limit test of field soil-calcium bentonite clay mixes variation. it is observed that the liquid limit of soil gets decreases with adding of bentonite clay and then suddenly increases in 19% bentonite clay mixing.

PLASTIC LIMIT:

S.No	Properties	Test method	Average value	Permissible value
1	Soil Plastic limit	IS-2720 Part-5 (1985)	14.28%	Less than or equal to 40

RESULT:

  The result of the plastic limit test of field soil calcium bentonite clay mix. It is clear that the plastic limit of soil gets suddenly increases in 18% bentonite mix. It is clear that the plastic limit of soil with calcium bentonite mixes more stabilized comparison than the normal soil.

PROTOR COMPACTION TEST:

• To determine the relationship between water content and dry density of soil.
• This test also covers relationship between penetration resistance and water content for the compacted soil.

S.NO	% of  admixtures	OMC in %	MDD (G/CC)
1	Clay soil+4% bentonite+0.5% coir	18	2.04
2	Clay soil+4% bentonite+1% coir	16	2.06
3	Clay soil+4% bentonite+1.5% coir	14	2.065
4	Clay soil+4%  bentonite+2% coir	16	2.065

CALFORINA BEARING RATIO TEST:

S.NO	% of admixtures	CBR % For 2.5 mm penetration	CBR % For 5.0 mm penetration1
1	Clay soil +4% Bentonite +0.5% coir	3.57	3.15
2	Clay soil +4% Bentonite +1% coir	5.13	5.01
3	Clay soil +4% Bentonite +1.5% coir	5.27	5.11
4	Clay soil +4% Bentonite +2% coir	5.52	5.23

UNCONFINED COMPRESSIVE STRENGTH TEST WITH ADMIXTURE:

The purpose of the test is to obtain the quantitative value of compressive and shearing strength of soil in an undrained state.

S.NO	% of Bentonite+ coir	Shear strength (kg/cm2)
1	0	0.295
2	5	0.413
3	10	0.423
4	15	0.442
5	20	0.431

4. CONCLUSION:

• Calcium bentonite act an additive in the clayey soil in which its presence in short function affects the plasticity of the soil & long term function will affects its strength & durability .
• It is one of the economical method of soil stabilization of clay soil where the raw materials like coir & calcium bentonite are cheaper when compared to other method of stabilization of soil.
• Calcium bentonite & coir are naturally occurring material & can be used for construction purposes which also leads to increases in bonding properties of Clayey  soil which also leads to reduction in swell & shrink Behavior of clayey soil.
• It has been found that with the increases in percentage of calcium bentonite and coir there is An  CBR value of 2.5mm & 5.0mm penetration when compared to conventional clayey soil.

Credit: This project on “Stabilization Of Clay Soil Using Coir Fibre And Calcium Bentonite” was completed by Mr. Devakandhan¹, Ajay kumar R², Monesh M³ Pavithiran M⁴, Surya prakash M⁵ from Department of Civil Engineering, Sri Sairam engineering college Chennai.

5. REFERENCES:

[1]. Raja Kumar (2014) “California bearing ratio of expansive Subgrade stabilized with waste materials” International Journal of Advanced Structures and Geotechnical Engineering Vol. 03, No. 01, January 2014.
[2]. Chen, F. H. (1975) Foundations on Expansive Soils, Elsevier Scientific Pub. Co  Amsterdam. Adeniji, F. A. (1991) “Recharge function of vertisolic vadose Zone in sub-Sahelian Chad Basin”. Proceeding 1^st International Conference on Arid Zone Ideology Hydrology and water resources, Maiduguri pp. 331 – 348.
[3]. V Rama Susheel Kumar1, J Vikranth2 “Application of Coconut Coir and Fly ash in Subgrade strengthening” The International Journal Of Engineering And Science (IJES) || Volume || 3 || Issue || 12 || December- 2014 || Pages || 48-54|| ISSN (e): 2319–1813 ISSN (p): 2319 – 1805.
[4]. Choudhary A. K., Gill K. S. and Jha K.N. (2011); “Improvement in CBR values of expansive soil subgrade using geosynthetics”. Proc. Indian Geotechnical Conference, Kochi, pp.569-572.
[5]. Brajesh Mishra, “A Study on Engineering Behaviour of Black Cotton Soil and its Stabilization by Use of Lime”, International Journal of Science and Research (IJSR), Volume 4 Issue 11, November 2015, pp- 290-294.
[6]. Pavan Kumar P. V. S. N., (December 2005), ” Studies on Quick lime treated Black Cotton soils”, IGC- 2005, Ahmedabad, India, pp. 227- 230.
[7]. Haresh D. Golakiya, Chandresh D. Savani, “studies on geotechnical properties of black cotton soil stabilized with furnace dust and dolomitic lime”, International Research Journal of Engineering and Technology (IRJET), Volume: 02 Issue: 08 | Nov-2015, PP 810-823.
[8]. Vinayak Kaushal, Dr S.P.Guleri, “Geotechnical Investigation of Black Cotton Soils. International Journal of Advances in Engineering Sciences Vol.5, Issue 2, April 2015, pp-15-22.
[9]. Katare Rupal, Pande M. M. and Jain S.K., (October 2009), “Lime Stabilisation method for Black cotton soil of Gwalior Region”, ACSGE- 2009, BITS Pilani, India, pp. 1-8.
[10]. Al-KhafajI,  A. W. N., and Andersland, O. B. (1992). “Equations for Compression index Approximation. Journal of Geotechnical Eng. ASCE, 118(1), 148–153.